Energy Of Thin Film Research Articles

Evaluation of Band Structure of Single Crystalline Si-Rich SiSn thin Film

IntroductionSilicon Tin (Si1-x Sn x ) is supposed to transfer from the indirect bandgap to the direct bandgap by adding Sn with Si. Hence, it is expected to be applied to the next-generation optical devices such as Si photonics due to its high affinity with Si devices [1, 2]. The crossover point from the indirect bandgap to the direct bandgap has been estimated by various simulations. However, there is a large variation in the Sn fraction from approximately 25% [3] to 48.9% [4]. Therefore, it is essential to verify the bandgap energy and optical properties of Si1-x Sn x from the viewpoint of photonics application.In this study, we evaluated the band structure of single crystalline Si1-x Sn x films by Photoluminescence (PL) spectroscopy and Spectroscopic Ellipsometry (SE).Experimental methodTable 1 summarizes the specifications of Si1-x Sn x thin film samples used in this experiment. Si1-x Sn x thin films were grown on Si substrates by Molecular Beam Epitaxy (MBE) [5] or sputtering. Si1-x Sn x thin films (Sn fraction: 10 and 15%) were also grown on Si1-y Ge y buffer layer/ Si by MBE [2]. Epitaxial growth was confirmed by X-ray diffraction 2D reciprocal lattice space mapping (XRD-2DRSM) in all samples. Sn fraction as well as in-plane biaxial and out-of-plane strain were estimated by XRD-2DRSM. The Si thin film deposited on a Si substrate by sputtering was prepared as the reference.For PL measurements, a He-Cd laser (wavelength: 325 nm, excitation power: 15 mW) was used at the sample stage temperature of 10 K. For SE measurements, the xenon lamp with a wavelength range of 200-1600 nm was used as an excitation source, with the incident angle of 70 degrees.Results and DiscussionFigure 1 shows PL spectra of Si and Si1-x Sn x at the sample stage temperature of 10 K. Band-to-band luminescence spectra derived from Si1-x Sn x were observed from the single-crystal Si1-x Sn x (x=0.034, 0.060 and 0.10) samples which shifted toward the lower energy side with increasing Sn fraction. We calculated the indirect bandgap energy with the Transverse-Optical-phonon-assist energy and the band-to-band luminescence confirmed by PL measurements. As a result, the indirect bandgap energy of Si thin film was 1.157 eV, while the indirect bandgap energy of the other Si1-x Sn x were slightly lower around 1.151 eV. The indirect bandgap of Si1-x Sn x comparing among the three samples, Si0.966Sn0.034, Si0.94Sn0.06, and SiSn0.90Sn0.10/ SiGe buffer shifted slightly toward the lower energy side with increasing Sn fraction. Thus, a slight reduction in the indirect bandgap energy occurred with increasing Sn fraction.Figure 2 shows the imaginary part (ε2) of the complex dielectric function of (a) Si1-x Sn x (x=0.022, 0.034, 0.052, 0.060 and 0.079) and (b) Si substrate and Si thin film measured by SE. The origins of the sharp peaks are direct band transition, which are known as the critical points (CP). The optical transition energy E'0 at the Γ point and the optical transition energy E1 at the Λ point are approximately 3.4 eV in Si substrate. Hence, the origin of the peak at approximately 3.4 eV in Fig. 2 (a) is optical transitions at the Γ and Λ points. The optical transition energy indicates that they similarly shifted to the lower energy side with increasing Sn fraction. This suggests that the direct bandgap energy of Si1-x Sn x decreased. In addition, the peaks were observed at 2.8 and 2.0 eV. However, these may be due to factors other than Sn atoms addition, such as epitaxial related defects, since these peaks were also observed for Si thin film in Fig.2 (b).Figure 3 shows the direct bandgap energy of Si1-x Sn x and Si substrate from SE measurements. We found that the amount of change in the direct bandgap energy from SE results (more than 29 meV) is much larger than those of the indirect bandgap energy from PL results (less than 8 meV). Therefore, it is considered that the bandgap type approaches the direct bandgap with increasing Sn fraction. The crossover point predicted by our results is estimated to be about 47.2% of Sn fraction. This is close to the predicted value simulated by the density functional theory and the first-principles calculations [4] among various simulated values. In conclusion, we have clarified the correlation between the band structure and Sn fraction in single crystalline Si1-x Sn x .[1] M. Kurosawa et al., Appl. Phys. Lett. 106, 171908 (2015).[2] K. Fujimoto et al., Appl. Phys. Express. 16, 045501 (2023).[3] J. Tolle et al., Appl. Phys. Lett. 89, 231924 (2006).[4] Y. Nagae et al., Jpn. J. Appl. Phys. 56, 04CR10 (2017).[5] R. Yokogawa et al., ECS Trans. 98, 291 (2020). Figure 1

Optical Properties of Gold Nanoparticles Doped P3HT Nanowires Films

Poly (3-hexyl-thiophene-2,5-diyl) (P3HT) material is widely used as the benchmark of p-type semiconductors in organic photovoltaics due to its high conductivity and self-assembly into nanowires. In this study, gold-doped P3HT nanowires were synthesized using o-xylene, and their optical and electronic changes were investigated. P3HT nanowires were kept in the dark for 72 hours to obtain 60 – 80 nm diameter of nanowires. 1 mM of chloroauric acid doping was used as glass-coated P3HT nanowires were dipped repetitively into the chloroauric acid solution. It was found that visible absorbance intensity reduced and the calculated optical bandgap energy of P3HT nanowires thin film decreased as much as 0.08 eV after doping. FTIR and Raman show there are no extreme changes in P3HT conjugated backbones structure after doping meaning that the gold did not completely integrate within nanowires. From this observation, we discussed the feasibility of this coating method to produce metal-doped organic film and the required improvement to suit photonic device applications.

Williamson-hall analysis and absorption spectrum fitting in the estimation of crystallite size and band gap energy of CdZnS thin films

Williamson-hall analysis and absorption spectrum fitting in the estimation of crystallite size and band gap energy of CdZnS thin films

Interfacial carbon quantum dot thin film impacts on morphological and chemical structures of fluorine-doped tin oxide films

Morphology and chemical bonding states, including surface roughness, film density, F-doping, and oxygen vacancy (VO) concentration directly affect the electrical and optical properties of fluorine-doped tin oxide (FTO) films. In this study, morphology and chemical bonding states of FTO films are engineered simultaneously by introducing a carbon quantum dot (CQD) thin film as an interface layer during ultrasonic spray pyrolysis deposition. The abundant oxygen-containing surface functional groups and large surface free energy of the CQD thin film promoted (200) oriented crystal growth and accelerated nucleation of FTO, resulting in smooth and dense FTO film morphology. The abundant carboxyl surface functional groups on the CQDs generate active F− species that are effectively doped into SnO2. Formic acid, formed by dissociation of the carboxyl group, can serve as a strong reducing agent for extracting oxygen atoms from the SnO2 lattice, thereby increasing the VO concentration. The accelerated F-doping and VO concentration result in the generation of additional free electrons. The effects of the optimized CQD on the morphological and chemical structures of FTO films are demonstrated by their superior electrical (sheet resistance of ∼5.7 Ω/□) and optical properties (visible transmittance of ∼85.9 %) compared with bare FTO. Moreover, CQD/FTO used as transparent conducting electrodes in electrochromic (EC) application exhibited improved EC performances, including fast switching speeds (5.3 s and 2.3 s for bleaching and coloration, respectively) and high coloration efficiency (81.1 cm2/C) compared to that of bare FTO.

Augmentation of room temperature gas sensing properties of PANI thin films by 100 keV Ar+ ion irradiation

Polyaniline thin films were subjected to irradiation with Ar+ ions at four different concentrations: 1 × 1014, 1 × 1015, 1 × 1016, and 3 × 1016 ions/cm2, with an energy of 100 keV to improve the sensing ability. Field emission scanning electron microscope (FESEM) images revealed that the porosity as well as surface area of thin films increase significantly with the increase in fluence dose. The bandgap energy of the irradiated thin films found to decrease from 3.04 to 2.36 eV, whereas, the number of carbon atoms per cluster are found to increase from 127 to 211 atoms with increasing the Ar+ ions dose from 1x1014 to 3x1016 ions/cm2. The ratios of the areas under the curves AQ/AB are increased from 0.221 to 0.456 as the Ar+ ion fluence dose rate rose from 0 to 3 × 1016 ions/cm2. Thus, it can be assumed that the electrical conductivity of the PANI films increase with the Ar+ ion fluence dose rate via carbonaceous clustering, and the scission of polymer chains. The as-deposited PANI thin film demonstrated the lowest sensing response at approximately 33 %, while the thin film irradiated with the highest dose of 3 × 1016 ions/cm2 exhibited the highest sensing response at around 1119 % for methanol vapors at a concentration of 100 ppm.

Efek Penambahan Diethanolamine dan Suhu Kalsinasi terhadap Energi Gap Lapisan Tipis CuSnO3

This study focuses on the synthesis of CuSnO3 thin films using the sol-gel dip coating method, with a particular emphasis on the effects of diethanolamine (DEA) addition and calcination temperature on the bandgap energy. The successful addition of DEA significantly influenced the reduction of the bandgap energy of CuSnO3 thin films, decreasing from 3.21 eV (without DEA) to 2.11 eV (optimal DEA addition, 1.5 mL), as characterized by UV-DRS. Furthermore, different calcination temperatures yielded varying bandgap energies, with the lowest bandgap energy observed in samples calcined at 550°C. This research provides valuable insights into the manipulation of CuSnO3 thin film properties for potential applications in optoelectronic devices and other emerging technologies.

Microstructures and mechanical properties of Sb-doped ZnO thin films deposited on a-plane sapphire substrates

The structural features and nanomechanical properties of ZnO and Sb-doped (1.0 at%) ZnO (SbZO) thin films deposited on a-plane sapphire substrates by radio-frequency (RF) magnetron sputtering are comparatively investigated in this study. The X-ray diffraction and atomic force microscopy analyses indicated that both ZnO and SbZO thin films were highly (002)-oriented albeit with somewhat different grain structure and surface morphologies. Nanoindentation results of both films exhibited apparent discontinuities (so-called pop-ins) in the load-displacement curves (P-h curves), while no discontinuity was observed in the unloading segment of the P-h curves. By using a Berkovich nanoindenter operating with the continuous contact stiffness measurement mode, the obtained hardness and Young's modulus of ZnO (SbZO) thin films are 7.3 ± 0.2 (8.5 ± 0.4) GPa and 259.6 ± 17.8 (327.4 ± 13.9) GPa, respectively. Furthermore, the facture toughness and fracture energy of ZnO and SbZO thin films obtained by Vickers indentation were also compared.

Studying the Effects of Annealing and Surface Roughness on Both the Magnetic Property and Surface Energy of Co60Fe20Sm20 Thin Films on Si(100) Substrate

In this study, Co60Fe20Sm20 alloy was employed for sputter deposition onto Si(100) substrate within a high vacuum environment, and subsequent thermal treatment was conducted using a vacuum annealing furnace. Thorough measurements and analyses were carried out to evaluate how various film thicknesses and annealing temperatures affect the material. The investigations encompassed observations of structural and physical properties, magnetic traits, mechanical behavior, and material adhesion. The results from the four-point probe measurements clearly demonstrate a trend of decreasing resistivity and sheet resistance with increasing film thickness and higher annealing temperature. Analysis through atomic force microscopy (AFM) shows that heightened annealing temperature corresponds to decreased surface roughness. Furthermore, when analyzing low-frequency alternating current magnetic susceptibility (χac), it became evident that the maximum magnetic susceptibility value consistently rises with increased film thickness, regardless of the annealing temperature. Through magnetic force microscopy (MFM) observations of magnetic domain images in the films, it became apparent that there was a noticeable reduction in the brightness contrast of the magnetic domains. Furthermore, nanoindentation analysis reveals a clear trend. Elevating the film thickness leads to a reduction in both hardness and Young’s modulus. Contact angles range between 67.7° and 83.3°, consistently under 90°, highlighting the hydrophilic aspect. Analysis of surface energy demonstrates an escalation with increasing film thickness, and notably, annealed films exhibit a substantial surge in surface energy. This signifies a connection between the reduction in contact angle and the observed elevation in surface energy. Raising the annealing temperature causes a decline in surface roughness. To summarize, the surface roughness of CoFeSm films at different annealing temperatures significantly impacts their magnetic, electrical, and adhesive properties. A smoother surface reduces the pinning effect on domain walls, thus enhancing the χac value. Furthermore, diminished surface roughness leads to a decline in the contact angle and a rise in surface energy. Conversely, rougher surfaces exhibit higher carrier conductivity, contributing to a reduction in electrical resistance.

Tailoring of the Structural, Optical, and Electrical Characteristics of Sol-Gel-Derived Magnesium-Zinc-Oxide Wide-Bandgap Semiconductor Thin Films via Gallium Doping.

The Ga-doped Mg0.2Zn0.8O (GMZO) transparent semiconductor thin films were prepared using the sol-gel and spin-coating deposition technique. Changes in the microstructural features, optical parameters, and electrical characteristics of sol-gel-synthesized Mg0.2Zn0.8O (MZO) thin films affected by the amount of Ga dopants (0-5 at%) were studied. The results of grazing incidence X-ray diffraction (GIXRD) examination showed that all as-prepared MZO-based thin films had a wurtzite-type structure and hexagonal phase, and the incorporation of Ga ions into the MZO nanocrystals refined the microstructure and reduced the average crystallite size and flatness of surface roughness. Each glass/oxide thin film sample exhibited a higher average transmittance than 91.5% and a lower average reflectance than 9.1% in the visible range spectrum. Experimental results revealed that the optical bandgap energy of the GMZO thin films was slightly higher than that of the MZO thin film; the Urbach energy became wider with increasing Ga doping level. It was found that the 2 at% and 3 at% Ga-doped MZO thin films had better electrical properties than the undoped and 5 at% Ga-doped MZO thin films.

Influence of Cu incorporation on structural, optical, and electronic structure of ZnO thin films deposited by laser ablation

Pristine and Cu-doped ZnO thin films with 3 wt%, 5 wt% & 7 wt% Cu concentrations were deposited by pulsed laser deposition (PLD) to observe the effect of incorporation of Cu in ZnO lattice towards their structural, optical and electronic structural properties. Structural investigations were carried out using X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), and Field Emission Scanning Electron Microscopy (FESEM). Optical studies were performed using UV–Visible (UV–Vis), Photoluminescence, and RAMAN spectroscopies. The electronic structure of the films was studied using X-Ray absorption spectroscopy (XAS). All the films are oriented along (002) plane with wurtzite hexagonal symmetry, confirmed from XRD results. The optical band gap energy of ZnO thin films decreases from 3.26 eV to 3.0 eV with increasing Cu concentration from 0 to 7 wt% respectively. The various structural defects were confirmed from PL spectrums. The variation in the hybridization of O 2p states with Cu doping concentration is understood by XAS study.

Enhancement of sensitization and electron transfer by kumkum dye in dye-sensitized solar cell applications

An anatase-based nanostructured TiO2 thin film paint was sprayed on FTO conducting glass to create dye-sensitized solar cells. Turmeric (Curcuma longa) and CaCO3 were used as natural sensitizers (DSSCs). FTIR and UV-Vis spectrophotometry was used to analyze the functional groups and optical characteristics of the dyes at absorbing photon energy of the semiconductor thin films, respectively. Both the XRD and UV results show that TiO2 has an anatase phase structure that is consistent with its broadband gap nature. The PL spectra of natural dyes were examined to determine their optical properties and the intensity of PL emission reported a bandgap of 4.72 eV and 4.95 eV respectively. The efficiency of the DSSC using Kumkum dye in ethanol is 0.9%, whereas in DI is 0.2%. Curcumin is a flavonoid polyphenol which is a very effective light-harvesting derivative required for the creation of charge carriers and generation of electric current has been found to be present in turmeric extract and is subjected to the coloring of natural sensitizers which enhance the absorption coefficient. Data Availability StatementThe datasets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Comparative investigation on physicochemical and photocatalytic properties of CuS and Al3+ doped CuS thin films

By using the chemical bath approach, CuS, and Al-doped CuS thin films were formed onto glass substrates. To enhance the photocatalytic capabilities of the traditional CdS thin film, Al3+ ions were used as doping element. Investigations were done into how the amount of Al doping affected the physical characteristics of CuS films by varying Al content as 2 wt%, 4 wt%, 6 wt%, and 8 wt%). The bandgap energy, thickness, morphology, and crystalline structure of CuS and Al-doped CuS thin films were examined. By using FTIR and FT-Raman studies, the functional groups contained in the CuS and Al-doped CuS thin films were observed. EDS was used to estimate the elemental components that are present in the prepared thin films. Degradation of the textile dyes rhodamine B (RhB) and methylene blue (MB) was used to examine the photocatalytic characteristics of the produced films. Among the produced films 8 wt% Al-doped CuS thin film showed high efficiency in degradation of both MB (98 %) and RhB (98 %) dyes.

Effect of Surface Defect Engineering on Proton Conductivity in Yttrium-Doped Barium Zirconate Thin Films

Yttrium-doped barium zirconate (BZY) has been considered as a potential electrolyte candidate for intermediate-to-low temperature protonic ceramic fuel cell applications. However, the transport properties of BZY are often limited by the formation of highly resistive space charge zones at lattice discontinuities, such as lattice defects and surfaces. Unlike lattice defects, how to reduce the space charge effects at surfaces remains less explored. In this regard, surface defect engineering can be a meaningful way to regulate the proton transport of BZY by tailoring the space charge distribution close to the surface. Here, the Ar and/or O2 plasma was used to prepare BZY thin films with different levels of surface defects. The results of electrochemical impedance spectroscopy and detailed structural characterization suggest that the plasma treatment is effective in improving the proton conductivities and lowering the activation energy of BZY thin films through the generation of negatively charged barium vacancy defects and the enrichment of yttrium dopants on the surface.

Isomeric acceptors incorporation enables 18.1% efficiency ternary organic solar cells with reduced trap-assisted charge recombination

The donor–acceptor miscibility is one of the most critical factors in controlling the active layer morphologies with multiple components. However, how to practically select the third component with the desired miscibility for efficient ternary organic solar cells remains unresolved. Herein, we demonstrate that the surface energy of thin films could be manipulated by altering the weight ratios of the isomeric acceptors in the blend films and, therefore, the regulation of donor–acceptor miscibility. When the acceptor weight ratio (M−Cl:O-Cl) is 1:0.3, low miscibility (χ = 5.43 × 10-2K) with PM6 is achieved, and the power conversion efficiency of organic solar cells composed of PM6:M−Cl (17.1%) is enhanced to 18.1% (PM6:M−Cl:O-Cl). The increased power conversion efficiency resulted from the surface energy-driven active layer morphology and donor–acceptor phase separations, associated with the significantly lower energetic disorder, trap density, and thus reduced free charge recombination. Our findings underline the significance of the isomeric approach to managing the blend film surface energy and, therefore, the donor–acceptor miscibility for improving the device performance, providing guidelines for the fabrication of high-performed ternary OSCs and material designs.

Electrochemical properties of CoFe2O4 thin film electrodes prepared by spray pyrolysis

CoFe2O4 thin films have been prepared by chemical spray pyrolysis at various substrate temperatures and were characterized for structural, morphological, compositional, optical, electrical and electrochemical properties. X-ray diffraction studies confirmed the spinel cubic phase formation with crystallite size in the range of 15 to 23 nm. Field emission scanning electron microscopy images showed porous spherical granular like surface morphology. Optical bandgap was observed in the range of 2.33 eV to 2.54 eV with direct allowed type transitions. The electrical resistivity measurement confirmed semiconducting behaviour. CoFe2O4 electrode prepared at 425 °C showed specific capacitance of 543 Fg−1 at scan rate of 5 mVs−1 from cyclic voltammetry and 575 Fg−1 at current density of 0.5 Ag−1 from galvanostatic charge-discharge within potential window of 0 V to 0.55 V in aqueous 1 M KOH electrolyte. The specific energy and specific power of CoFe2O4 thin film prepared at 425 °C were found to be 17.86 Whkg−1 and 1108 Wkg−1 respectively at current density of 4 Ag−1. CoFe2O4 thin film prepared at 425 °C exhibited 93.03% retention of its specific capacitance after 1000 cycles at a current density of 1 Ag−1. Electrochemical impedance spectroscopy analysis confirmed the superior electrochemical properties of CoFe2O4 thin films. The good electrochemical performance suggests use of CoFe2O4 thin films for supercapacitors.

Influence of nanoparticle size on the characterization of ZnO thin films for formaldehyde sensing at room temperature

Thin films of zinc oxide (ZnO) were deposited on glass substrates using chemical bath deposition (CBD) by varying the deposition time from one to three hours. The structural, morphological, optical, and responsiveness of the ZnO thin films to formaldehyde gas at room temperature were studied with respect to the nanoparticle grain sizes. The average grain sizes of the ZnO nanoparticles deposited for 1, 2, and 3 h were 19.6, 25.1, and 31.5 nm, while the average crystallite sizes were 73.07, 88.28, and 95.25 nm, respectively. The band-gap energies of the ZnO thin films deposited for 1, 2, and 3 h were found to be 3.27, 3.28, and 3.29 eV, respectively. Energy dispersive X-ray (EDX) analysis of the synthesized ZnO nanoparticles confirmed their purity, and water contact angles indicated that longer deposition durations with larger grains enabled them to be more hydrophobic. The formaldehyde gas-sensing experiments showed the ZnO thin films deposited for larger grain sizes had a better gas response at room temperature than the rest. The maximum responses of the samples deposited for 1, 2, and 3 h were 5.5, 11.0, and 17.8, respectively, at 400 parts per million (ppm) of formaldehyde gas. Additionally, it was observed that the samples deposited for 1, 2, and 3 h could detect as low as 100, 25, and 12 ppm of formaldehyde, respectively.

Study the effect of Ni doping on structural, optical and electrical properties of Zn1-xNixO thin films deposited by spray pyrolysis technique

The effect of Ni doping on structural, optical and electrical properties of deposited Zn1-xNixO thin films on glass substrate by spray pyrolysis technique has been studied. The main objective of this research is to study the change of the physical and optical properties of Zn1-xNixO thin films that are fabricant to semiconductor with different doping levels x. These levels are 0 at.%, 2 at.%, 4 at.%, 8 at.% and 12 at.%. The transmission spectra show that the Zn1-xNixO thin films have a good optical transparency in the visible region from 88 to 95%. The optical gap energy of the Zn1-xNixO thin films varied between 3.25 and 3.35 eV. The urbach energy varied between 65 and 230 meV. However, the Zn0.88Ni0.12O thin films have many defects with maximum value of urbach energy. The Zn0.88Ni0.12O thin films have minimum value of optical gap energy. The Zn0.88Ni0.12O thin films have maximum value of the electrical conductivity which is 9.40 (Ω.cm)-1 . The average electrical conductivity of our films is about (7.52 (Ω.cm)-1 ). XRD patterns of the Zn1- xNixO thin films indicate that films are polycrystalline with hexagonal wurtzite structure.

Effect of Annealing Temperature on Excitonic Binding Energy and Other Optical Properties of Mn-Ni Co-Doped Transparent ZnO Thin Films

In this work, low cost sol-gel spin coating technique was successfully employed to deposit Mn-Ni co-doped ZnO (MNZO) thin films on glass substrates. Structural, topographical and optical properties of MNZO thin films were studied in the light of XRD spectra, Raman spectroscopy, SEM, AFM, UV-visible spectroscopy and photoluminescence spectroscopy. XRD study revealed that all annealed ZnO thin films have hexagonal wurtzite structure with (002) preferred orientation along c-axis. Hexagonal wurtzite structure for all films has been confirmed by Raman spectra which show optical phonon modes. Grain size, micropores and RMS surface roughness showed an increasing trend with the rise in annealing temperature as revealed by SEM and AFM images. The experimental data of absorption coefficient was analysed in the light of hydrogenic excitonic model to estimate excitonic binding energy (R) and other optical parameters of the prepared thin films. The excitonic binding energy decreased from 71.55 to 49.2 meV on increasing annealing temperature from 200° to 500°C. Peaks corresponding to UV, violet, green, yellow and orange were clearly observed in photoluminescence spectra for all annealed thin films. The ultraviolet peak shifted towards lower wavelength (blue-shifted) as the annealing temperature was increased. All the peaks in visible region were attributed to transition between complex intrinsic and extrinsic defects. Such films can be a potential candidate for efficient lasers and LEDs and for variety of optoelectronic device applications.

Impact of ethyl cellulose variation on microstructural and electrochemical properties of spin coated YSZ electrolyte thin films for SOFCs: Slurry composition evolution

The present work meticulously highlights the physical and electrochemical properties of slurry spin coated Yttria Stabilized Zirconia (YSZ) electrolyte thin films for solid oxide fuel cell (SOFC) applications wherein the concentration of ethyl cellulose (EC) is varied from 3.5 wt% to 6.5 wt% in the EC/YSZ/terpineol slurry. The TGA of the prepared mixtures reveals the complete mass removal of EC in temperature range of 380–400 °C. The dense and crack-free YSZ thin films on NiO/YSZ anode composites are developed by performing four separate coating cycles where each cycle is preceded by baking the films at 380 °C. The prepared YSZ electrolyte thin films showed polycrystalline nature with cubic phased prominent reflection corresponding to plane (111). The crystallite size of YSZ thin films is determined from W–H and Scherrer's relations which is obtained in the range of 18–26 nm and 21–26 nm, respectively. The 3D AFM projection shows hill-like topography where the average roughness is found to be increased from 3.01 nm to 8.49 nm with an increase in the EC content. FESEM analysis unveils smooth morphology along with the presence of some abscission zones in YSZ thin films after the removal of EC. The electrochemical properties are explored by fitting equivalent electrical circuit to the Nyquist data which confirms electrolytic response of the prepared coatings. The thermal activation of ionic conduction has been verified by observing the Arrhenius plots where conductivity is found to be varied in range 10 −4 -10 −5 S/cm with the respective increase in EC content. The activation energies of YSZ electrolyte thin films are found to be in the range of 1.09–1.18 eV which are slightly higher as compared to that of bulk YSZ.

THE ACTIVATION ENERGY OF PURE POLYETHYLENE OXIDE AND POLYETHYLENE OXIDE DISPERSED WITH IODINE

The activation energy of thin films polymers made of pure polyethylene oxide (PEO) andPEOdoped with 0.1 % by weight iodine were investigated. The observed physical constants of the cast thin films, such as the activation energy were determined. The films were prepared by the casting method using electricity. This study investigated the variation of the activation energy of thin films of pure (PEO) andPEOdoped with 0.1 % wt. iodine with a frequency in the range of 200-800 kHz and with the temperature in the range of 30-55°C. The results proved that there is a significant change in the values of the activation energy (Ea) of both thin films being studied with the variation of frequency and temperature. It was found that the values of the (Ea) of the prepared thin films decrease withPEOdoped with 0.1 % wt. iodine. The Ea values for both thin films studied decrease with the increase in frequency and temperature.